In communication systems, Push-to-Talk (PTT) is a process of having conversations or talking in a half-duplex manner, including via a two-way radio system, using a trigger mechanism to switch from voice reception mode to transmit mode. Each discrete transmission of audio is generally known as a “talk-burst”. As described herein, PTT systems can be implemented through wireless systems such as European Telecommunications Standards Institute Digital Mobile Radio (ETSI-DMR), Terrestrial Trunked Radio (TETRA), Project 25 (P25), Land Mobile Radio (LMR), Long Term Evolution (LTE), Code Division Multiple Access (CDMA), Global System for Mobile Communications (GSM), and the like. PTT is often used in conjunction with group distribution, such that audio from any one user in a group is distributed to all other users in the same group.
It is anticipated that future PTT systems may include an ability to present time delayed audio to users, i.e., delayed talk-bursts. Certain talk-bursts may be presented to one or more users in a time delayed fashion (with respect to “live”) under certain circumstances. On occasion, a receiving user may desire to respond to the presentation of a delayed talk-burst. Because the presentation of the audio may be significantly delayed with respect to the time when it originated from the sourcing user, it is not always appropriate to simply direct talk-back audio to the talk-group or talker (in the case of a 1-to-1 call) originally associated with the delayed audio. Among other reasons, the talker may no longer be available or the context of the talk-group discussion may have shifted to a new topic.
Accordingly, there is a need for a method and apparatus for delayed talk-back in PTT systems that determines an appropriate talk-back action when a user is hearing a combination of real-time and delayed audio.
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The apparatus and method components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.